package com.carl.math;

import java.util.Scanner;

public class question_04 {

    public static void main(String[] args) {
        //加权平均数
        Scanner scanner = new Scanner(System.in);
        double a = scanner.nextDouble();
        double b = scanner.nextDouble();
        System.out.printf("avg = %.4f",(a*3.5+b*7.5)/11);
    }
}
